import java.sql.*;
import java.util.Scanner;

public class Main {
    public static void main(String[] args){

        //查询
        //m1();
        //条件查询
        //m2();
        //增加
        //m3();
        //删除
        //m4();



        //1.加载驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        }
        //2.获取连接 (url username password)
        String url="jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
        try {
            Connection connection = DriverManager.getConnection(url, "root", "Zyk20040710.");
            if(connection !=null){
                System.out.println("连接成功");
            }
            //3.写sql
            String sql="select * from user where name like ?";
            //4.预编译sql
            PreparedStatement preparedStatement=connection.prepareStatement(sql);
            //5.有参数设置参数
            //6.执行sql
            ResultSet resultSet= preparedStatement.executeQuery();
            //7.遍历结果集
            while(resultSet.next()){
                int id=resultSet.getInt(1);
                String name=resultSet.getString(2);
                String pass=resultSet.getString(3);
                System.out.println(id+"----"+name+"----"+pass);
            }
            //8.关闭资源
            resultSet.close();
            preparedStatement.close();
            connection.close();

        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }

    private static void m1() {
        // 1、加载驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");

            // 2、获取连接 (url username password)
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            Connection connection = DriverManager.getConnection(url, "root", "Zyk20040710.");
//            if (connection != null) {
//                System.out.println("连接成功");
//            }
            // 3、写sql
            String sql = "select * from sys_user";

            // 4、预编译sql
            PreparedStatement preparedStatement = connection.prepareStatement(sql);

            // 5、有参数设置参数

            // 6、执行sql
            ResultSet resultSet = preparedStatement.executeQuery();

            // 7、遍历结果集
            while (resultSet.next()){
                int id = resultSet.getInt(1);
                String name = resultSet.getString(2);
                String pass = resultSet.getString(3);
                System.out.println(id+"-----"+name+"------"+pass);
            }

            // 8、关闭资源
            resultSet.close();
            preparedStatement.close();
            connection.close();


        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
    private static void m2(){
        // 1、加载驱动
        try {

            // Scanner
            Scanner sc = new Scanner(System.in);
            System.out.print("请输入你要查询的姓名：");
            String word = sc.next();

            Class.forName("com.mysql.cj.jdbc.Driver");

            // 2、获取连接 (url username password)
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            Connection connection = DriverManager.getConnection(url, "root", "Zyk20040710.");
//            if (connection != null) {
//                System.out.println("连接成功");
//            }
            // 3、写sql
            String sql = "select * from sys_user where name like ? ";

            // 4、预编译sql
            PreparedStatement preparedStatement = connection.prepareStatement(sql);

            // 5、有参数设置参数
            preparedStatement.setObject(1,"%"+word+"%");

            // 6、执行sql
            ResultSet resultSet = preparedStatement.executeQuery();

            // 7、遍历结果集
            while (resultSet.next()){
                int id = resultSet.getInt(1);
                String name = resultSet.getString(2);
                String pass = resultSet.getString(3);
                System.out.println(id+"-----"+name+"------"+pass);
            }

            // 8、关闭资源
            resultSet.close();
            preparedStatement.close();
            connection.close();
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }

    private static void m3(){
        Scanner sc = new Scanner(System.in);
        System.out.print("请输入要新增的姓名：");
        String name = sc.next();
        System.out.print("请输入要新增的密码：");
        String pass = sc.next();
        //1.加载驱动
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        }
        //2.获取连接 (url username password)
        String url="jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
        try {
            Connection connection = DriverManager.getConnection(url, "root", "Zyk20040710.");
            if(connection !=null){
                System.out.println("连接成功");
            }
            //3.写sql
            String sql="insert into user(name,pass)values(?,?)";
            //4.预编译sql
            PreparedStatement preparedStatement=connection.prepareStatement(sql);
            //5.有参数设置参数
            preparedStatement.setObject(1,name);
            preparedStatement.setObject(2,pass);
            //6.执行sql executeUpdate
            int result = preparedStatement.executeUpdate();
            //7.遍历结果集
            if(result>0)
                System.out.println("新增成功");
            //8.关闭资源
            preparedStatement.close();
            connection.close();

        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }
    private static void m4(){
        // 1、加载驱动
        try {

            Class.forName("com.mysql.cj.jdbc.Driver");

            // 2、获取连接 (url username password)
            String url = "jdbc:mysql://127.0.0.1:3306/jdbc?characterEncoding=utf-8";
            Connection connection = DriverManager.getConnection(url, "root", "Zyk20040710.");
//            if (connection != null) {
//                System.out.println("连接成功");
//            }
            // 3、写sql
            String sql = "delete from sys_user where id = ? ";

            // 4、预编译sql
            PreparedStatement preparedStatement = connection.prepareStatement(sql);

            // 5、有参数设置参数
            preparedStatement.setObject(1,"6");

            // 6、执行sql  executeUpdate
            int result = preparedStatement.executeUpdate();

            // 7、结果判断
            if (result > 0) {
                System.out.println("删除成功");
            }

            // 8、关闭资源
            preparedStatement.close();
            connection.close();


        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }

    }
}



